The problem of effectively protecting the rolling bearing which supports the wheel in motor bikes hubs, in particular on motor bikes intended for off-road use (cross, trial etc.) from external pollutants (water, mud, dust) arises, in particular in the presence of frequent washing of the motor bike with high-pressure water jets (pressure washers) and frequent disassembly of the wheel hub for maintenance and/or re-lubrication (grease application).
Until now, such problem has been solved by means of sealing devices comprising a stiff reinforcing insert, which is restrained to the wheel hub and which carries one or more additional lips, either crawling or not, known as dust seals, in addition to one or more dynamic elastic crawling sealing lips sliding on a wheel hub support pin or on a spacer carried by the pin, the pin in use being stationary and supported by the wheel shock absorbers. JP6001770A illustrates a particularly effective embodiment of such a solution.
However, the solution known from JP6001770A has relatively large axial dimensions, i.e. in the direction of the wheel support pin axis, which are incompatible with most applications. On the contrary, solutions based on additional sealing lips, possibly provided with particular geometries, while having smaller axial dimensions than the sealing device of JP6001770A are either not sufficiently effective or are relatively unreliable, in particular due to performance which decay over time.
It is the object of the present invention to provide a sealing device, in particular for wheel hubs of motor bikes, which can be inserted between two axial symmetry members relatively rotatable with respect to each other, which is free from the drawbacks described above, and which, in particular, has small dimensions, in particular in axial direction, high efficiency and reliability remaining constant over time, and high ease of assembly and disassembly, together with high simplicity and a relatively low production cost.